Important Questions (2 Marks): Life Processes - SSS 1 MCQ

Arteries are thick-walled blood vessels which pump blood at high pressure away from the heart. They do not have valves as their walls are highly muscular.

Topic in NCERT: The tubes – blood vessels

Line in NCERT: "Arteries are the vessels which carry blood away from the heart to various organs of the body. Since the blood emerges from the heart under high pressure, the arteries have thick, elastic walls."

The root has further extensions which increase the surface area for absorption.
These extensions are called root hair, which is present in all types of roots.

Topic in NCERT: Transportation in Plants

Line in NCERT: "The absorption of these substances therefore occurs through the part in contact with the soil, namely roots."

Stomata, which are part of the epidermal system in plants, facilitate transpiration. Transpiration mainly occurs through these stomata located in the leaves.

Topic in NCERT: Transport of water

Line in NCERT: During the day when the stomata are open, the transpiration pull becomes the major driving force in the movement of water in the xylem

Oxygenated blood carries O₂ to the various tissues, muscles, cells, et(c) from the lungs and heart, while deoxygenated blood carries CO₂ from the organs to the lungs which is removed from the body. In birds and mammals, it is essential to keep the oxygenated blood separated from the deoxygenated blood In this way, only highly oxygenated blood is sent out to the body's tissues for far more efficient diffusion into the cells of the body, giving them more 'fuel' to run cellular respiration in the mitochondria, to make ATP molecules to run the reactions that allow them to maintain body temperature in addition to running all of their metabolic reactions of the body. If they were not separated, it would probably take much longer to perform simple activities and metabolism would be reduced as a consequence.

Topic in NCERT: Oxygen enters the blood in the lungs

Line in NCERT: "The separation of the right side and the left side of the heart is useful to keep oxygenated and de-oxygenated blood from mixing. Such separation allows a highly efficient supply of oxygen to the body."

Arteries are the blood vessels which carry oxygenated blood from the heart to the organs. It breaks up into several branches of capillaries before entering the organs. These capillaries again reunite to form venules and ultimately veins which carry the deoxygenated blood towards the heart.

Topic in NCERT: The tubes – blood vessels

Line in NCERT: "Arteries are the vessels which carry blood away from the heart to various organs of the body."

The kidneys filter blood to remove urea and other wastes (A), maintain water balance (B), regulate salt levels (D), and form urine (E). However, they do not produce antibodies, which is the function of the immune system (B-lymphocytes).

Topic in NCERT :Excretion in Human Beings

The kidney is the main excretory organ in man. It helps in the filtration of blood and maintains osmoregulation. Accessory organs of excretion are liver, lungs, and skin. Small intestine and large intestine helps in the digestion of food whereas the heart is the main circulatory organ in the human body which helps in the transportation of blood.

Topic in NCERT: Excretory system in human beings

Line in NCERT: "The excretory system of human beings includes a pair of kidneys, a pair of ureters, a urinary bladder and a urethra."

When your systolic pressure is between 120 and 129 mm Hg and your diastolic pressure is less than 80 mm Hg, it means you have elevated blood pressure. Although these numbers aren't technically considered high blood pressure, you've moved out of the normal range.

Topic in NCERT: Blood pressure

Line in NCERT: "The normal systolic pressure is about 120 mm of Hg and diastolic pressure is 80 mm of Hg."

The sugars, synthesized in leaves (as a result of photosynthesis) are translocated downwards, upwards, and laterally to storage organs mainly through phloem. These sugars are translocated in the form of sucrose.

Topic in NCERT: Transport of food in plants

Line in NCERT: "the phloem transports products of photosynthesis from the leaves where they are synthesised to other parts of the plant."

The diastolic reading, or the bottom number, is the pressure in the arteries when the heart rests between beats. This is the time when the heart fills with blood and gets oxygen. A normal diastolic blood pressure is lower than 80. A reading of 90 or higher means you have high blood pressure.

Topic in NCERT: Blood pressure

Line in NCERT: "The normal systolic pressure is about 120 mm of Hg and diastolic pressure is 80 mm of Hg."

The majority of carbon dioxide molecules (85 percent) are carried as part of the bicarbonate buffer system. In this system, carbon dioxide diffuses into the red blood cells. Carbonic anhydrase (CA) within the red blood cells quickly converts the carbon dioxide into carbonic acid (H₂CO₃).

Topic in NCERT: Transportation in Human Beings

Line in NCERT: "Carbon dioxide is more soluble in water than oxygen is and hence is mostly transported in the dissolved form in our blood."

The enzymes lipase and trypsin are present in the pancreatic juice that break down emulsified fats and degrade proteins respectively.

Topic in NCERT: Nutrition in Human Beings

Stomach secretes the enzyme pepsin and pancreas produces trypsin. Both of them break down protein.

Topic in NCERT:  Nutrition in Human Beings

Line in NCERT: "The digestion in stomach is taken care of by the gastric glands present in the wall of the stomach. These release hydrochloric acid, a protein digesting enzyme called pepsin, and mucus." "The pancreas secretes pancreatic juice which contains enzymes like trypsin for digesting proteins."

Autotrophic mode of nutrition involves the use of sunlight, chlorophyll, carbon dioxide, and water to produce starch.

Topic in NCERT: Autotrophic Nutrition

Line in NCERT: "Carbon and energy requirements of the autotrophic organism are fulfilled by photosynthesis. It is the process by which autotrophs take in substances from the outside and convert them into stored forms of energy. This material is taken in the form of carbon dioxide and water which is converted into carbohydrates in the presence of sunlight and chlorophyll."

The pancreas contains all kinds of enzymes that can digest proteins, fats, and carbohydrates.

Topic in NCERT: Nutrition in Human Beings

Line in NCERT: "The pancreas secretes pancreatic juice which contains enzymes like trypsin for digesting proteins and lipase for breaking down emulsified fats."

The nephron is the structural and functional unit of the kidney. It is responsible for filtering blood and forming urine through processes like filtration, reabsorption, and secretion.

Topic in NCERT: Excretion

Line in NCERT: The basic filtration unit in the kidneys is a cluster of capillaries, called a glomerulus, which is enclosed in a cup-like structure called Bowman’s capsule.

Mucus is a viscous secretion that protects the inner lining of the stomach from the action of HCl.

Topic in NCERT: Nutrition in Human Beings

Line in NCERT: "The mucus protects the inner lining of the stomach from the action of the acid under normal conditions."

Transpiration creates a suction force that helps in the upward movement of water through the xylem vessels in plants. This process is called transpiration pull.

Topic in NCERT: Transport in Plants

Line in NCERT: During the day, when the stomata are open, the transpiration pull becomes the major driving force in the movement of water in the xylem.

The build-up of lactic acid in our muscles while running (less oxygen conditions) causes cramps.

Topic in NCERT: Respiration

Line in NCERT: "this build-up of lactic acid in our muscles during sudden activity causes cramps."

Red blood cells (RBCs) contain hemoglobin, which binds to oxygen and transports it to various parts of the body.

Topic in NCERT: Transportation in Animals

Line in NCERT: Hemoglobin, a respiratory pigment present in red blood cells, has a very high affinity for oxygen.